Preheat oven to 400F. Heat oil in a large, heavy-based, flameproof dish over high heat. Cook shanks, in two batches for 4 - 5 minutes on each side or until browned on all sides. Remove to a plate
Melt butter in dish until sizzling. Add flour and cook for 1 minute. Remove from heat & slowly add stock, wine & cranberry sauce. Season with salt & pepper, return to heat and bring to a boil. Add lamb and rosemary.
Cover dish, transfer to oven & bake for 1 hour. Remove lid & bake for a further 30 minutes or until shanks are tender. Serve with potato & beans.